Let-off mechanism for looms



(No Model.)

J. A. BERGAN.

LET-OFF MBGHANISM'FOR LOOM-S.

No. 331,274. Patented Dec. 1, 1885.

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N. PETERS. Photo-Litho rapher. Washinglun. n. C.

UNITED STATES PATENT OFFIC JOHN A. BERGAN, OF HOLDEN, ASSIGNOR OF ONE-HALF TO CHARLES W. GILBERT, OF WORCESTER, MASSACHUSETTS.

LET-OFF MECHANISM FOR LOOMS.

SPECIFICATION forming part of Letters Patent No. 331,274, dated December 1,, 1885.

Application filed February 25, 1884. Serial No. 122,012. (No model.)

To all whom it may concern.-

Be it known that I, JOHN A. BERGAN, a citizen of the United States, residing at Holden, in the county of W'orcester and State of Massachusetts, have invented certain new and useful Improvements in Let-Off Mechanism for Looms; and I declare the following to be a description of my said invention, sufficiently full, clear, and exact to enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

The objects of my present invention are to provide a convenient and eflicient let-off mech anism for regulating the tension and delivery of warps on looms, to afford means for the ready adjustment of the let-off to different degrees of tension, and to provide facilities for the convenient detachment of the levers for releasing the friction-bands when it is desired to change the warp-beam. These objects I attain by the mechanism illustrated in the drawings and herein described, the particular subject-matter claimed being hereinafter definitely specified.

In the drawings, Figure 1 shows my improved let-off as applied to use in connection with a loom and its warp-beam. Fig. 2 is a face view of the adjusting mechanism on a larger scale. Fig. 3 is a vertical sectional view showing details of construction. Fig. 4 is a horizontal sectional view showing the buttonplate and levers. Fig. 5 is a plan view of the bottom plate, showing the pockets for the lever ends and the guide-notch.

A designates the back girt of the loomframe, and B denotes the warp-beam, both of which may be of any of. the usual forms and arrangement.

S denotes the friction stirrups or bands, arranged around the heads of the beam B, the ends thereof being connected with and drawn down by straining-levers L, which are properly fulcrumed at Z and extend inward along the girt A to the supporting and pressure devices, which engage their inner ends, and by means of which a greater or less degree of friction is brought upon the beam-heads.

Gdenotes the attaching-bracket of the let off mechanism, made in proper form to support the operating parts, and adapted to be bolted or secured to the rear part of the girt A, as illustrated.

D denotes a revoluble shaft or spindle supported vertically in bearings c c on the bracket (3, said shaft being provided with suitable shoulders or collars, c, at its top end, whereby it is retained in the upper bearing, 0, as shown, and having a screw-thread, (1, upon its upper portion, while it is provided at its lower end with a wrench head, handle, wheel D, or equivalent means, whereby it can be readily revolved when desired.

F indicates a rotative disk or plate mounted to'slide up and down on the spindle D, the disk being carried upon a sleeve or guide, E, surrounding the spindle D and supported in the bearing 0. Said plate is adapted for buttoning down or engaging the ends of the levers L, and to have vertical action in connection with said lever ends. It is furnished with a handle, f, or means whereby it can readily be turned, and with openings or slots 6 e, of suitable form to permit the passage of the ends of the levers when said slots are brought into coinciding positions therewith. The slots 6 are so located in the plate F that when the plate is in normal position the slots do not coincide with the position of the lever ends, but by turning said plate on its axis the lovers can be released.

I indicates adisk or piece arranged beneath the plate F and retained from rotative action by a notch or lugs, 41, that engage with a rib or vertical guide, a, on the bracket 0, and which disk serves for retaining the levers L in proper position laterally. The part I is. provided with recesses or pockets m m, into which the ends of the levers are dropped, and in which said ends are retained by the button or plate F turned over them.

Ii indicates a nut arranged on the screwthreaded portion of the spindle D and fitted to be non-revoluble by engagement with the vertical guide-rib a of the supporting-bracket C, so that when the spindle is revolved the said nut will move up and down along the screw-thread d of the spindle, for changing its position or height in relation to the fulcrum point Z of the levers L and the stirrup-connections thereto.

J indicates a coiled spring or springs arranged between the plate F and nut K, for giving the required pressure on the levers L, the expansive force of said springs being exerted to force the plate F downward upon the levers L, and the degree ofrsuch pressure is regulated by the nut K. When two springs, J and J, are used, one of them can be made shorter than the other, so that both will exert their force when the nut Kis low down on the spindle, and only one of them will eXert its force on the plate and levers when the nut is at the upper part of the spindle. When a full beam of warp is put into the loom, the nut K may be run down so that the springs will eX- ert a strong pressure on the levers L, thus giving increased friction on the heads of the beam, and the friction can be gradually reduced, as required, as the warp is taken off the beam, by occasionally turning the spindle D for raising the nut K, thus accommodating the mechanism to the requirements of the decreasing size of the warp-cylinder as the warp is run off the beam. The levers L can be readily released, when desired, by simply swinging the handle of the plate F to the right or left (see dotted lines, Fig. 4) sufficiently to bring one of the slots 0 over the end of a lever, and then raising the end of thelever up through such slot.

Among the advantages incident to my invention it may be mentioned that a more uniform cloth can be made, the delivery of the warp being more regular, a more accurate adjustment of pressure can be effected, and less jar and irregularity of action results than with an ordinary weight let-off. The opera tor can cause the loom to put in or leave out one or more picks per inch by aslight turn of the hand-wheel D, and the operation of disconnecting for change of beams is rendered more convenient and expeditious than with the let-off devices heretofore in ordinary use.

What I claim as of my invention, and desire to secure by Letters Patent, is-

1. The combination,with friction-stirrups S, of the straining-levers L, the slotted plate F, engaging the ends of said levers, the vertical screw-threaded spindle D, the spring J, arranged thereon above said plate, and the adjusting nut K, substantially as and for the purpose set forth.

2. The combination, with the back girt ina loom, of the bracket 0, having the flange a, the rotative spindle D, the non-rotative nut fitted thereon, the plate F, the spring J, the straining-levers L, and stirrups S, substantially as and for the purpose set forth.

3. The button-plate F, having slots e e, and the under plate, I, having recesses m m, and retaining-notch 43, in combination with the bracket 0, having aguide-flange, a, the straining-levers L, stirrups S, spindle D, and a spring, J, substantially as and for the purpose set forth.

4. The combination, with the friction-stirrups S and straininglevers L, of the bracket 0, the threaded spindle D, mounted in bearings on said bracket and provided with handwheel D, the plate F, having slots 6 e, the guide-sleeve E, surrounding said spindle, the plate I, provided with pockets on m, for receiving the ends of said levers, and lugs for engagement with the guide-flange a, the nonrotating nutK, and the springs J, coiled about the spindle between said nut and plates, substantially as and for the purpose set forth.

fitness my hand this 16th day of February,

JOHN A. BERGAN.

Witnesses:

GHAs. H. BURLEIGH, S. R. BARTON. 

